LANSING — Large-scale commercial dog breeding kennels would be regulated and limited by the state in a bill under consideration by the Michigan Senate.

Senate Bill 560 would take state regulations that cover pet shops and animal control shelters and apply them to kennels with more than 15 female dogs over the age of four months that are used for breeding. It also would ban kennels from having more than 50 breedable female dogs over the age of four months.

Several animal welfare organizations pushed for the measures, saying they'll help prevent so-called "puppy mills" or "puppy farms" that mass produce dogs but often put the animals in poor conditions.

The Senate Agriculture Committee heard testimony on Thursday but did not vote on the bill, which has bipartisan support.

"I have been in some horrific, I mean horrific places," said Anne Burns, deputy director of Ingham County Animal Control. She told lawmakers she saw "deplorable conditions" when officials seized 77 dogs from a home in Livingston County.

"I think that this bill will help folks ... like us to go in and regulate these breeders and stop the atrocities from happening, hopefully," she said.

Supporters say they want state registration along with more power to regulate the kennels beyond existing state animal cruelty laws.

Several other states, including those surrounding Michigan, have breeder regulations, according to the Michigan Humane Society.

Bob Darden, president of the Michigan Association for Pure Bred Dogs, said he supports licensing and enforcement of existing laws to protect animals, but he doesn't think the state should limit the number of dogs that a kennel could keep.

"We believe that there are enough laws on the books that would ensure animal welfare upon inspection and licensing of facilities," he said. "But placing an arbitrary number on the definition is just adding another layer of legislation that's not needed."

He said that simply having a large number of dogs doesn’t mean they’re treated poorly, and having a small number doesn’t ensure they’re kept in humane conditions.

SB 560 also would specify the amount of time a shelter would have to hold a dog or cat before the shelter could give it up for adoption, sell it or euthanize it. The time varies from two to seven days depending on the animals' situation.

Supporters say those shorter hold times will help shelters place more pets, especially cats, into homes. Longer hold times often lead to pet illnesses, they say.

The bill would ban pet shops, shelters or large-scale commercial breeders from ending an animal's life by any means other than euthanasia, which it defines as "the humane death of an animal through instantaneous unconsciousness and immediate death..."

Other parts of the bill would ensure dogs and cats have proper health certificates and vaccinations before coming into the state to be sold or adopted, according to bill sponsor Sen. Steve Bieda, D-Warren.